Spark plug



R. C. BERRY.

SPARK PLUG.

APPLICATION man JULY 9,1919.

Patented June 13, 1922..

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I @Mofa/vlag@ lllllll ROBERT C. BERRY, 0F INDIANAPOLIS, INDIANA, ASSIGNOR T0 DANIEL W. RITTER, 0F

INDIANAPOLIS, INDIANA.

SPARK PLUG'.

specification of Letter-gramm. Patented June 13, 1922.

Application filed July 9, 1919. Serial No. 309,698.

To all t may concern.'

BeA it known that I, ROBERT C. BERRY, av

citizen of the United States, residing at Indianapolis, in the county of Marion and State of indiana, have invented a new and useful Spark Plug, of which the following is a specification. f

It is the object of myfinvention to. provide a spark plug in which the spark gap .is adjustable from the outside, without removing the spark plug from the engine; in which the adjustment of the spark gap is indicated on the outside; and in which the electrode may bemade to clean itself when necessary by heating by the burning gases within the engine, and this cleaning may be controlled from the outside without removing the spark plug from the engine.

The accompanying drawing illustrates my invention; Fig; .1' is an elevation of a spark plug embodying my invention, with 'some ot the parts 'in section; Fig. 2.is a section on the line 2-2 of Fig. 1; Fig. 3 isa perspecf tive view of the manipulating and indicating means for the movable electrode; and Fig. 4 is a sectional detail of the outer end of the fixed electrode.

The spark plug comprises the usual shell 10 arran for mounting on 'the' engine, and a clampmgmember 11 arranged to clamp theV usual porcelain insulating member 12 in lace. p Extending axially throughlthe insulator 12 is a rod 13, which at its outer end is both screw-threaded and Hattened and at its inner end is bent to form an eye 1t. The manner in which this rod 13 is clamped in the insulator 12 is immaterial, save that such clamping is by a clamping nut 15 mounted on the screw threads at theouter end and by the tightening and loosening of which the rod 13 may be clamped or unclamped. Also.

mounted on the outer end 'of vthe rod 13, he-

tween the clamping nut 15. and the end of theinsulator 12, is a washer-like. member 1 6,-l

provided' with .a hole 17 which has dat sides to correspond with those of the rod- 13st), that such member 16 and the rod 13 will v The member 16 is pro#` vided with a thumb piece 18 by which it mayv he manipulated togturn the rod 13, and alsoY is provided with a ates with a scale 20 the insulator 12 to which the rod 13 is pointer 19 which coi-operwhich may be marked on indicate the position to turned.

loosening the clamping nut fixed electrode 21, asis clearlfrom Fig. 2

. the engine; and

the fixed electrode', where screw threads cation with a Extending transversely through the eye 14 is a fixed electrode 21; which is mounted 1n the side wall of the shell 10, usually by japress lit, and extends through such side wall at a point above the usual shoulder 22 with which the shell is provided to bear agalnst endof the fixed electrode 21 is in thel exposed part of the shell. 'l rlhe fixed electrode 21 extends substantially centrally through the eye 14; butthe diameter of such fixed Velectrode is materially smaller than the diameter of the eye 14, sothat when the plane Yof the eye isgperpendicular to such fixed electrode the spark gap between the two electrodes is quite large. rod 13 about its axis, which may be done by 15 and manipulatingethe rod by the thumb piece 18 of the mem made either perpendicular or oblique to the 7 ap distance between those parts of the thus varying the sparkthe fixed electrode an eyev 14 which lie in the plane of the fixed electrode perpendicular to the axis of the rod 13. By this adjustment, the spark gap may be made anything'desired. Proper indication of the spark gap distance is given by the pointer 19 on the scale 20. This adjustment of the spark gap distance may be made without disturbing the spark plug as a whole, and without dismounting it from may even be made while the engine is in operation, so that the'efiect of such adjustment may be noted in the engine operation. y

The stationary electrode 21 is preferably a tube, and does not extend completely across the opening provided in the shell 10 and in which opening the electrodes are located, so that one end of such fixed electrode is open within such space. The other .end of it projects outside the shell 10, is screw-threaded, and on it is vmounted a cap 23. When this cap is tightened, it closes the outer end of the tubular electrode 21. However, by loosening the 'cap 23, the outer end of the tubular electrode 21 is opened to the atmosphere, through. a longitudinal groove 24 along the of such cap and in communiperipheral hole 25. Figs. 1 and 4 show the cap tightened and loosened respectively. When the cap 23 is loosened r 16, the plane of the eye 14 may be the engine cylinder, so that the outer By turning the tive position,

while the engine is in operation, some of the burning gases from within the combustion space 0i the engine are forced out through the tubular electrode, and these heat such electrode suiliciently to burn od any carbon deposit which may have accumulated thereon. ln this way, the electrode may be cleaned when desired.

l claim as my invention:

1. ln a spark plug, the combination of suitable electrode-supporting means including a shell and a porcelain tube, a rod mounted in and positively axially clamped in said porcelain tube but rotatably adjustable therein about its axis, said rod at its inner end being provided with an odset portion which vconstitutes one of the electrodes, and a second electrode mounted on said electro-supporting means and co-operating with the first electrode to form the spark gap, said second electrode extending transversely of said rod past the axis thereof, the distance between said two electrodes being adjustable by such rotative adjustment of such rod.

2. ln a spark plug, the combination of electrode-supporting means including ashell and porcelain tube, an axially extending rod mounted in said porcelain tube and positively axiall clamped therein but rotatably adjustable t erein about its axis, said rod having an odset portion at its inner end and rotative adjusting means at .its outer end, indicating means associated with the outer end of said rod for indicating its rotaand a member extending transversely of said rod past the axis thereof and co-operating with said offset portion to form a spark gap the length of which is adjustable by the rotative adjustment of said rod.

3. ln a spark plug, the combination of electrode-supporting means including a shell and porcelain tube, an axially extending rod mounted in said porcelain tube andpositively axially clamped therein but rotatably adjustable therein about its axis, said rod having an offset portion at its inner end and rotative adjusting means at its outer end, and a member cooperating with said offset portion to form a spark gap the length oi which is adjustable by the rotative adjust ment of said rod, said member' extending transversely oi said rod and substantially through the rotative axis thereof.

4l. ln a spark plug, the combination ot electrode-supporting means, an axially extending rod accessible at its outer end and provided at its inner end with an eye which Larnaca forms one of the electrodes, and a second electrode extending transversely through said eye, the distance between said second electrode and the sides of said eye being adjustable by the rotative adjustment of said ro 5. ln a spark plug, the combination of electrode-supporting means, an axially extending rod accessible at its outer end and provided at its inner' end with an eye which forms `one of the electrodes, a second electrode extending transversely through said eye, the distance between said second elecl trode and the sides of said eye being adj ustable by the rotative adjustment of said rod, said second electrode consisting of a tube mounted in and extending to the outside of said electrode-supporting means, and means for opening and closing the outer end of said tube.

6. ln a spark plug, the combination of electrode-supporting means including ashell and a porcelain tube, an electrode mounted in said porcelain tube, a second electrode carried by said shell, said second electrode extending transversely of the first and cornprising a tube extending to the outside of the shell, and a cap mounted on the outer end of said tube and adjustable to open and close it.

7. In a spark plug, the combination of electrode-supporting means including a shell and a porcelain tube, an electrode mounted in said porcelain tube, a second electrode carried by said shell, said second electrode extending transversely ot the first and comprising a tube extending to the outside of the shell, and a cap mounted on the outer end of said tube and adjustable to open and close it, said tube and cap being associated so that ,by the adjustment of the cap an opening of variable size to` the atmosphere is provided.

8. ln a spark plug, the combination of electrode-supporting means, two electrodes mounted therein and insulated from each other, one of said electrode comprising a rod having an eye at its inner end, and the other electrode comprising a rod transverse to the first rod and extending through said eye` the rod having the eye being rotatively adjustable about its axis to vary the distance between said eye and the other rod.

lx1-witness whereof, l have hereunto set my hand at indianapolis, indiana, this 3rd day of July, it. D. one thousand nine hundred and nineteen.

RBEBT C. BERRY. 

